How To Give Bumper Repairs A Perfect Finish

22 September 2022 Automotive

Restoring The Structural Strength

Minor damage to a car bumper is frequently in the form of a dent which can often be repaired by simply applying hot water or air to the area until the dent pops out of its own accord, leaving only minor surface blemishes to be treated. But if the bumper or plastic trim is split it will need further work to restore its structural strength. There are several ways of doing this, including

Hot Stapling And Plastic Welding

This method presses heated metal staples into the plastic on either side of the crack on the rear of the bumper. The plastic melts, embedding the staple into the surface and hardening again as it cools. Flat strips of plastic welding rod can be applied on top of the staples to embed them deeper, and this is melted onto the bumper plastic with a flat-headed soldering iron.

Stainless Steel Mesh And Plastic Welding

This uses a similar method to hot stapling but doesn’t require a special hot stapler or stapes. A patch of stainless steel mesh is cut to size and applied over the crack on the rear of the bumper and pressed into the plastic with a flat-headed soldering iron. When the plastic has cooled and hardened, strips of flat plastic welding rod are placed across the mesh and melted onto the surface, embedding the mesh deeper and providing additional strength.

Restoring The Surface

Once the bumper is intact again, it’s time to restore the surface and this will generally require some filling and sanding, even if the crack is only a hairline.

Flexible Filler For Plastic Trim And Bumpers

To fill a crack in a plastic bumper or trim professionally and permanently you need to use a flexible two-component filler such as ProXL.

Easy to sand and with a very fine structure to resist pin-holing, PlastiFill is a highly flexible filler with excellent adhesion and resistance to weather and chemicals, making it a perfect product for automotive trim repair. It is applied in the same way as a conventional two-pack car body filler.

While many modern cars feature bumpers and trims that are finished in the same paint as the car panels, those on some cars and many commercial vehicles are made of textured self-coloured plastic. Once the damage has been stabilised and filled, it’s time to restore that OEM look.

Giving Texture Back To Bumpers And Trims

Available in a choice of black or clear, ProTex Textured Aerosols from ProXL will quickly restore the original texture to bumpers and trims. Supplied in a 500ml can, they are easy to apply and feature a dual nozzle system, giving a choice of coarse or fine texture from the same tin.

ProTex Textures are also easily overcoated with ProXL PlastiColour topcoat paints, which we will come to shortly.

Applying The Finishing Coat

With the bumper or trim now repaired and smooth (or textured, as the case may be), it’s time to prepare it for the top coat.

Promoting Paint Adhesion

While paint adhesion to plastic bumpers and trims isn’t as straightforward as it is on primed body panels, using an adhesion promoter will significantly improve the result.

PlastiGrip from ProXL is a fast-drying, clear adhesion promoter that will prepare the repaired surface perfectly for top coating within 10-30 minutes.

Adding The Colour Coat

Once the adhesion promoter is dry you can add the final coat. If the bumper or trim is the same colour as the rest of the car, you’ll use paints that match the OEM colour reference and follow the instructions, but what if the bumper or trim is self-coloured plastic?

PlastiColour plastic bumper and trim paints from ProXL come in a choice of nine tints that match the most commonly used plastic trim colours:

  • Jet Black
  • Black 1
  • Traffic Black
  • Smoke Grey
  • Dark Grey
  • Mid Grey
  • Mid Grey 2
  • Mid Grey 3
  • Light Grey

Does A Bumper Repair Kit Contain Everything I Need?

An online search for ‘plastic bumper repair kit’ is likely to result only in products used to repair structural damage to the bumper or trim, such as hot staplers and plastic welders.

For the rest of the repair, from filling and texturing to topcoat, the PlastiColour Bumper Repair Kit from ProXL is a perfect choice. This contains everything you need to get started, in a convenient storage box:

All products are completely compatible with each other and can be replenished from the ProXL standard range. For further information on automotive refinishing products, speak to the ProXL team on 01634 823900 or send them a message via their online contact form.